libgo/syscalls/socket_linux.go

   1 // socket_linux.go -- Socket handling specific to Linux.
   2
   3 // Copyright 2010 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 package syscall
   8
   9 import "unsafe"
  10
  11 const SizeofSockaddrInet4 = 16
  12 const SizeofSockaddrInet6 = 28
  13 const SizeofSockaddrUnix = 110
  14 const SizeofSockaddrLinklayer = 20
  15 const SizeofSockaddrNetlink = 12
  16
  17 type SockaddrLinklayer struct {
  18         Protocol uint16
  19         Ifindex  int
  20         Hatype   uint16
  21         Pkttype  uint8
  22         Halen    uint8
  23         Addr     [8]byte
  24         raw      RawSockaddrLinklayer
  25 }
  26
  27 func (sa *SockaddrLinklayer) sockaddr() (*RawSockaddrAny, Socklen_t, int) {
  28         if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {
  29                 return nil, 0, EINVAL
  30         }
  31         sa.raw.Family = AF_PACKET
  32         sa.raw.Protocol = sa.Protocol
  33         sa.raw.Ifindex = int32(sa.Ifindex)
  34         sa.raw.Hatype = sa.Hatype
  35         sa.raw.Pkttype = sa.Pkttype
  36         sa.raw.Halen = sa.Halen
  37         for i := 0; i < len(sa.Addr); i++ {
  38                 sa.raw.Addr[i] = sa.Addr[i]
  39         }
  40         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), SizeofSockaddrLinklayer, 0
  41 }
  42
  43 type SockaddrNetlink struct {
  44         Family uint16
  45         Pad    uint16
  46         Pid    uint32
  47         Groups uint32
  48         raw    RawSockaddrNetlink
  49 }
  50
  51 func (sa *SockaddrNetlink) sockaddr() (*RawSockaddrAny, Socklen_t, int) {
  52         sa.raw.Family = AF_NETLINK
  53         sa.raw.Pad = sa.Pad
  54         sa.raw.Pid = sa.Pid
  55         sa.raw.Groups = sa.Groups
  56         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), SizeofSockaddrNetlink, 0
  57 }
  58
  59 type RawSockaddrInet4 struct {
  60         Family uint16;
  61         Port uint16;
  62         Addr [4]byte /* in_addr */;
  63         Zero [8]uint8;
  64 }
  65
  66 func (sa *RawSockaddrInet4) setLen() Socklen_t {
  67         return SizeofSockaddrInet4
  68 }
  69
  70 type RawSockaddrInet6 struct {
  71         Family uint16;
  72         Port uint16;
  73         Flowinfo uint32;
  74         Addr [16]byte /* in6_addr */;
  75         Scope_id uint32;
  76 }
  77
  78 func (sa *RawSockaddrInet6) setLen() Socklen_t {
  79         return SizeofSockaddrInet6
  80 }
  81
  82 type RawSockaddrUnix struct {
  83         Family uint16;
  84         Path [108]int8;
  85 }
  86
  87 func (sa *RawSockaddrUnix) setLen(int) {
  88 }
  89
  90 func (sa *RawSockaddrUnix) getLen() (int, int) {
  91         if sa.Path[0] == 0 {
  92                 // "Abstract" Unix domain socket.
  93                 // Rewrite leading NUL as @ for textual display.
  94                 // (This is the standard convention.)
  95                 // Not friendly to overwrite in place,
  96                 // but the callers below don't care.
  97                 sa.Path[0] = '@';
  98         }
  99
 100         // Assume path ends at NUL.
 101         // This is not technically the Linux semantics for
 102         // abstract Unix domain sockets--they are supposed
 103         // to be uninterpreted fixed-size binary blobs--but
 104         // everyone uses this convention.
 105         n := 0;
 106         for n < len(sa.Path) - 3 && sa.Path[n] != 0 {
 107                 n++;
 108         }
 109
 110         return n, 0
 111 }
 112
 113 type RawSockaddrLinklayer struct {
 114         Family   uint16
 115         Protocol uint16
 116         Ifindex  int32
 117         Hatype   uint16
 118         Pkttype  uint8
 119         Halen    uint8
 120         Addr     [8]uint8
 121 }
 122
 123 type RawSockaddrNetlink struct {
 124         Family uint16
 125         Pad    uint16
 126         Pid    uint32
 127         Groups uint32
 128 }
 129
 130 type RawSockaddr struct {
 131         Family uint16;
 132         Data [14]int8;
 133 }
 134
 135 // BindToDevice binds the socket associated with fd to device.
 136 func BindToDevice(fd int, device string) (errno int) {
 137         return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device)
 138 }
 139
 140 func anyToSockaddrOS(rsa *RawSockaddrAny) (Sockaddr, int) {
 141         switch rsa.Addr.Family {
 142         case AF_NETLINK:
 143                 pp := (*RawSockaddrNetlink)(unsafe.Pointer(rsa))
 144                 sa := new(SockaddrNetlink)
 145                 sa.Family = pp.Family
 146                 sa.Pad = pp.Pad
 147                 sa.Pid = pp.Pid
 148                 sa.Groups = pp.Groups
 149                 return sa, 0
 150
 151         case AF_PACKET:
 152                 pp := (*RawSockaddrLinklayer)(unsafe.Pointer(rsa))
 153                 sa := new(SockaddrLinklayer)
 154                 sa.Protocol = pp.Protocol
 155                 sa.Ifindex = int(pp.Ifindex)
 156                 sa.Hatype = pp.Hatype
 157                 sa.Pkttype = pp.Pkttype
 158                 sa.Halen = pp.Halen
 159                 for i := 0; i < len(sa.Addr); i++ {
 160                         sa.Addr[i] = pp.Addr[i]
 161                 }
 162                 return sa, 0
 163         }
 164         return nil, EAFNOSUPPORT;
 165 }